the obama administration is sending letters to school districts across the country. it will call for, quote, reasonable modifications for students with disabilities. for example, a flashing light that goes off at the same time as the starting gun for a track athlete who cannot hear. 12 states already require accommodations. schools that do not comply could lose federal funding. and we've learned that president obama has chosen his next chief of staff. trusted adviser and national security expert dennis mcdonough will take over for jack lew. lew is the president's nominee for treasury secretary. mcdonough has been advising president obama on foreign policy for nearly a decade and has played a key role in all the president's major national security decisions, including the end of the iraq war, the repeal of don't ask, don't tell, and the withdrawal from afghanistan. an official announcement is expected in about an hour. >>> the president's former challenger mitt romney will be in town today for a rare appearance. he's attending a luncheon hosted by philanthropist kathl